There are actually TWO caves in and around Boerne, Texas. I’ve already posted about Cascade Caverns, but don’t miss the Cave Without a Name.
Their website features a very nice page about karsts, aquifers, and cave chemistry that would enhance older students’ understanding of Texas geography. They also offer a camping and a variety of tours and pricing to fit individuals, families and larger groups. Temperatures in the cave are a constant 66 degrees, so if you don’t have time to go now, pencil it is for a cool summer activity!